Vacuum pump



Dec. 20, 1966 K. R'. MacKENznE 3,292,844

VACUUM PUMP Filed May 23 1962 Uff.

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United States Patent Office 3,292,844 Patented Dec. 20, 1966 3,292,844VACUUM PUMP Kenneth R. MacKenzie, Pacific Palisades, Calif., assignor,

b'y mesne assignments, to Robert A. Cornog, Woodland Hills, Calif.

Filed May 23, 1962, Ser. No. 197,074 24 Claims. (Cl. 230-69) The presentinvention relates to a vacuum means and, more particularly, to a vacuumpump for producing a very high vacuum.

It is frequently desirable to carry on certain types of processes andexperiments in an enclosure from which the atmosphere has been removed.Heretofore, the at mosphere has usually been removed by means of amechanical vacuum pump. Such pumps are ordinarily very effective inremoving the atmospheric gases from a container and can produce vacuumsof substantial proportions. However, there is naturally a limit to theamount of vacuum which they can effectively create. More particularly,`a mechanical pump of high quality may be effec-tive to produce a vacuumon the order of about -3 millimeters of mercury. As a vacuum approachesthis magnitude, the number of gas molecules remaining in the containeris relatively small with substantial distances therebetween. In factthere is sufficient space between the molecules to permit electrons totravel through the vacuum with a low probability of collision with anygas molecules. Although a vacuum of the foregoing magnitude is adequatefor most vacuum processes, as the accuracy or precision of processes andexperiments increase, it has been found that even the small number ofmolecules present a vacuum on the order of 10'"3 millimeters of mercurymay be sufficient to cause contamination. As a result, it has becomeincreasingly necessary to produce vacuums of even greater magnitude.Heretofore in order to accomplish this, it has been necessary to resortto complex multi-stage mechanical pumps or other complicated, delicateand expensive means that have been somewhat effective to produce greatervacuums. However, such devices and the vacuums they produce are notentirely satisfactory.

It is now proposed .to provide a vacuum pump which will overcome theforegoing diiculties. More particularly it is proposed to provide avacuum pump which is not only simple and reliable in operation, but isalso very effective to produce a very high vacuum. This is to beaccomplished by providing a first housing that encloses a first regionof high vacuum and which is adapted to be interconnected with thecontainer wherein the high vacuum is to be created. In addition, asecond housing is provided that encloses a second region of low vacuumand which is adapted to be operatively interconnected with aconventional mechanical vacuum pump. A passage of restricted size isprovided between the two regions so that the conventional pump may beeffective to remove the atmosphere from the high and low vacuum regions.Electron accelerating means are also provided for directing a stream offree electrons through the first region so as to ionize at least aportion of the gas molecules in the first region. The resultant ionizedgas molecules will have an electrical charge that may be attracted by acharge of opposite polarity. Accordingly, an electrode may be disposedadjacent the passage way to produce an electric field that will beeffective to attract the ionized gas molecules through the passageway`and into the second region where the mechanical pump may remove them.It may thus be seen that a vacuum may be created that is much greaterthan the vacuum that can be created by a mechanical pump.

These and other fea-tures and advantages of the present invention willbecome readily apparent from reading the following detailed descriptionof one embodiment thereof, particularly when read in connection with theaccompanying drawings wherein like reference numerals deS- ignate likeparts and wherein FIGURE l is a transverse cross sectional view of avacuum pump embodying one form of the present invention; and

FIGURE 2 is a perspective view of the vacuum pump of FIGURE 1.

Referring to the drawings in more detail, the present invention isparticularly adapted to be embodied in a vacuum pump l which may beconnected to la container (not shown) in which it is desired to create avacuum, which is of greater magnitude than can be created by means of aconventional mechanical pump. By way of example, the vacuum may be onthe order of 106 millimeters of mercury, whereas a mechanical pump willordinarily only produce a vacuum on the order of 10-3 millimeters ofmercury.

The present pump 10 includes a first housing 12 that includes a header14 with a conduit 16 projecting from the center thereof. The conduit 16is adapted to be connected to the container by any suitable means thatwill permit gas to flow therethrough. The opposite side of the header 14includes at least one arm that extends therefrom. Although `any desirednumber of arms may be employed, in the present instance, there are twoarms 18 and 2f) which are substantially parallel to each other.

Each of the arms 18 and 20 includes an upper Wall 22 and 24 and a lowerwall 26 and 28 which are substantially parallel to each other. The walls22 and 26 and the walls 24 and 28 are separated from each other by apredetermined space. In addition side walls 30 and 32 are secured to thetop and bottom walls so as to en-` close the spaces therebetween. Thesespaces communicate with the interior of the header 14 and form firstregions 34 and 36 of high vacuum.

A second housing 38 is also provided which includes a top wall 40, abottom wall 42 and a substantially cylindrical side wall 44. These walls40, 42 and 44 are al1 secured together to form an air tight structurewhich encloses a region 46 of low vacuum. A duct 47 may be provided thatcommunicates with the region 46 and is `adapted to be connected to aconventional mechanical vacuum pump (not shown). The side wall 44includes a pair of openings through which the two arms 18 and 20 mayextend. The inner ends of vthe arms 18 and 20 will thus be disposedinside of the second housing 38 and completely surrounded by the region46 of low vacuum.

Each of the arms 18 and 20 m-ay include an opening 48 or 50 in the topwall 22 or 24 and the bottom wall 26 and 28 adjacent the inner endsthereof. All of the openings 48, 50, 52 and 54 are preferably coaxialwith the axis of the cylindrical wall 44. The openings will thus bedisposed in the center of the low vacuum region 46 and in substantialalignment with each other. It may thus be seen that any gas moleculesthat are present in either region 34 or 46 may flow through any of theopenings and into the other region 46 or 34.

Electron accelerating means 56 may be provided for directing a stream ofelectrons through the vacuum regions 34 and 46. In the present instance,this means includes an electrically conductive cylinder 58Y that ismounted between the two -arms 18 and 20 so as to be concentric with thecylindrical wall 44. The cylinder 58 will thus be axially aligned withthe openings 48 to 54. A conductor 60 may be provided that has one endthereof connected to the cylinder 58. The other end of the conductor 60extends through an insulator 62 mounted in the side wall 44 and isconnected to a coil 63 which is coupled to the output of an oscillator64. The potential on the cylinder 58 will thus be made to oscillate. andproduce an electric force field or potential gradient inside of thehousing 3.8.

Since there will be some gas present inside of the housing 38, therewill also be some free electrons in the vicinity of the cylinder 58. Thefield in the cylinder will react with any free electrons and alternatelyattract and repel them. As a result the electrons will oscillate axiallyof the cylinder 58. In order to control the direction of theseoscillations, a magnetic ux field may be created inside the housing 38.In the present instance, `this field is created by a magnetic circuitthat comprises a permanent magnet having a core disposed outside of thehousing 38. The pole faces 66 and 68 are disposed adjacent and parallelto the end walls 40 and 42. This magnet will thus produce a flux fieldwherein the lines of flux are substantially parallel to the passagewayformed by the openings 48, 50, 52 and 54 and the cylinder 58. Since anelectron traveling in a vacuum is constrained to follow magnetic fluxlines, any movement of the electrons will be axially of the cylinders 58and normal to the arms 1-8 and 20. Accordingly the electrons will travelthrough the second region 46 and through the pair of first regions 34and 36 enclosed inside of the arms 18 and 20.

In order to limit the distance that these electrons may travel, a pairof electrodes 70 and 72 may be disposed above and below the arms 18 and20 and in substantial alignment with the openings 48 to 54. lEach ofthese electrodes 70 and 72 may be connected with a source of negativepotential by means of an electrical conductor 74. This source will beeffective to maintain the electrodes at a suitable negative potential toproduce a strong repulsive force on any of the electrons in thevicinity. As a result after an electron has traveled through theopenin-gs 48 or 54 and the regions therebetween, it will be repelled andits excursion terminated. When the polarity of the cylinder 56 againreverses, the electron will travel in the opposite direction axiallyalong the magnetic lines through the arms 18 and 20 so as to be stoppedby the opposite electrode.

It may thus be seen that the electrons will oscillate along lthemagnetic lines of flux and between the two electrodes 70 and 72. In sodoing they will travel through the high vacuum regions 34 and 36 insideof the arms 18 and 20. During this portion 4of their journey,probability of lcolliding with at least Ia portion of any gas moleculesthat are present in the regions 34 and 36. When such a collision occursat least one electron in the molecular structure will be knocked out oforbit. Thus, after such a collision, there will be two free electronsand one positive ionized gas molecule. The two free electrons will thenproceed to oscilla-te axially of the flux field substantially asdescribed above.

In order to remove the ionized -gas molecule, electrodes 75 Iand 76 maybe disposed in the second or low vacuum region 46. Since the ion willpossess a positive net charge the electrodes 7'5 and 76 may be connectedto a negative potential on theA order of 100 volts by means of aconductor 78. These electrodes 75 and 76 will thus create anelectrostatic field which will extend through the openings 50 and 52 andinto the first regions-34 and 36. The resultant attractive forces uponthe positively charged ions will cause the ions to travel through theopenings 50 and 52 towards the electrodes 75 and 76. In addition, theelectrodes 70 and 72 will similarly attract positive ions through theopenings 48 and 54. Since the ions will not be constrained to travelalong the flux line, they will have a high probability of colliding withthe negative elec-` trodes. At the time of such a collision the gasmolecules will acquire an electron from the electrodes. The ions thenbecome neutrally char-ged and are disposed in the second or low vacuumregion 46. Since the resultant moleculehas no net electric charge ofeither polarity, it will be free to travel in a random pattern. As aconsequence few if any of the molecules will return through the openings48, 50, 52 and 54. Instead they will tend to remain in the second region46 whereby the vpump will tend to eventually remove the ion from theregion 46.

It may thus be seen that in order to employ the present pump 10 forcreating a very high vacuum in a container, the conduit 16 extendingfrom-the header 14 may be connected .to the containerwhereby the firstor high vacuum region inside of the housing 12 maybe interconnected withthe interior of the container and permit the free ow of gasestherebetween. At the same time,

the conduit 47 extending from the side of thefhousing 3'8 -may beconnected to a conventional vacuum pump whereby the second or low vacuumregion inside of the housing 38 will be interconnected with the pump andpermit gas to ow thereto.

in the second region 46 will decrease. This in turn will result in thegases in the container and in the first regions 34 and 36 to flowthrough the openings 48,` 50, 52 `and 54 and intol the second region 46.Eventually, as the4 pressure approaches the limits of the pump, thepressures in the two regions will become substantially equal. As i thevacuums in the two regions 34, 36 and 46 approach the limit of the pump,the various electrodes may all be energized. Since there will still besome gases present in the two regions 34, 36 and 46, there will also besome free electrons present around the electrodes. Thus the oscillationsof the potential on `the center 58 will cause these electrons `to bealternately attracted and repelled. Since the electrons must travelparallel to the direction of the flux field produced by the magnet, theywill move axially of the cylindrical electrode 58 and between theelectrodes and 72. When the electrons approach the end electrodes 70 and72,` the negative charges on the electrodes 70 and 72 will repel theelectrons and thereby provide an effective limit to the amount of axialtravel of the electrons. During these oscillations at least a portion ofthe electrons will travel through the first regions 34 and 36 inside ofthe arms 18 and 20. A portion of these electrons will collide with aportion of the gas molecules present around the openings 48, 50, 52 and54. The electrons will have sufficient energy or velocity to cause atleast one electron in the molecule to be knocked out of orbit. This willthus produce an ion having a net positive charge and a new freeelectron. The two electrons will Ithen continue to oscillate axially ofthe passage substantially as previously described.

The resultant ionized molecule will have a net positive charge and theelectric field from the negatively charged electrodes 70, 72, and 76will attract the positive ion. This will -cause the molecule to travelthrough the openings 48, 50, 52 and 54 and into the region 46 so as toVcollide with the electrodes 70,72, 75 and 76. This collision willpermit the molecules to thereby acquire a new electron and a neutral netcharge. Since the gas molecule will not be subject to any lforces fromthe magnetic field or the electrodes,`it will travel in a random mannerthrough the second region 46, although a few of these molecules may tendto travel back through an opening 48, 50, 52 `or 54, a large majority ofthe molecules will tend to remain in the second ,region 46 whereby theywill eventually be removed through the conduit 47 by the mechanicalpump. By thus continuously removing at least a portion of the gasmolecules present in the ends of the arms 18 and 20, the vacuum in thefirst region and in the container connected thereto will be increasedbeyond the capacity of the conventional pump.

It may thus be seen that a new and improved vacuum pump has beenprovided that will be very effective to produce high vacuums. Althoughthe present invention has been described in relation to one particularembodiment thereof, it will be readily apparent to persons skilled inthe art that numerous changes and modifications may be made theretowithout departing from the spirit of the invention. Accordingly, theforegoing disclosure is for illustrative purposes only and does notlimit the invention which is defined only by the claims which follow.

I claim:

1. In a device for transferring a gas from a region of high vacuum to aregion of low vacuum the combination of a passageway extending betweensaid regions, electrode means adjacent said passageway, and means forenergizing at least a portion of said electrode means with analternating voltage to cause free electrons to oscillate axially of saidpassageway and through said regions, and a collector disposed in theregion of low vacuum.

2. In a device for transferring a gas from a first region of high vacuumto a second region of low vacuum the combination of a passagewayextending between said regions, electrode means positioned in saiddevice andV adjacent said passageway, means for energizing saidelectrode means with an alternating potential to cause free electrons tooscillate axially of said passageway and through said first region withsufiicient velocity to ionize at least a portion of the gas in saidfirst region, and electrode means disposed in said second regionadjacent said passageway and having a polarity to attract ions in saidfirst region.

3. Means for transferring at least a portion of the gas present in afirst region of high vacuum into a second region of low vacuum, saidmeans comprising the combination of a passageway extending between saidregions for interconnecting said regions with each other, electronaccelerating means positioned adjacent the passageway for producing afield in the passageway, an alternating power supply interconnected withthe electron accelerating means for energizing the electron acceleratingmeans with a radio frequency potential of a suicient potential foraccelerating free electrons through at least said first region withsufiicient velocity to ionize at least a portion of any gas presenttherein, and an ion collector disposed in the region of low vacuum. y

4. Means for transferring at least a portion of the gas present in afirst region of high vacuum into a second region of low vacuum, saidmeans comprising the combination of a passageway extending between saidregions for interconnecting said regions with each other, electronaccelerating means positioned adjacent said passageway to create a eldin the passageway, an alternating power supply interconnected with theaccelerating means for producing an oscillating field in the passagewayfor causing free electrons to oscillate along paths extending axiallythrough at least the portion of the passageway in said first region withsuicient velocity to ionize at least a portion of said gas therein, andelectrode means disposed in said second region adjacent said passagewayand spaced from said paths to be separated from electrons beingaccelerated by said accelerating means, said electrode means having acharge thereon that creates a field that extends along said passagewayand into said first region for attracting ionized gas in said firstregion into said second region.

5. Means for transferring at least a portion of the gas present in afirst region of high vacuum to a second region of low vacuum said meanscomprising the combination of a passageway extending between saidregions for interconnecting said regions with each other so that gas mayflow between said regions, magnetic means disposed adjacent to saidpassageway for creating a flux field with the lines of flux extendingaxially of said passageway, cold electrode means juxtaposed to saidpassageway for creating a eld therein, and means for energizing saidelectrode means for causing the free electrons normally present in saidpassageway to oscillate along said ux lines in spaced relation to saidcold electrode means and between said regions with sufiicient velocityto ionize at least a portion of the gas .in said first region.

6. Means for transferring at least a portion of the gas present in a rstregion of high vacuum to a second region of low vacuum, said meanscomprising the combination of a passageway extending between saidregions for interconnecting said regions with each other so that gas mayow between said regions, magnetic means disposed for creating a ux fieldhaving the lines of flux therein extending axially of said passageway todefine a plurality of electron paths, electron accelerating meansdisposed adjacent said passageway for creating a field within saidpassageway for accelerating free electrons axially of said passagewayalong said paths defined by the flux lines, an alternating power supplyinterconnected with the electron accelerating means for causing theelectrons to oscillate along said paths and between said regions withsufiicient velocity to cause ionization of at least a portion of saidgas in said first region to thereby form a plasma having ionized gas andfree electrons, said plasma being electrically non-conductive at the gaspressures present in the first region, and an electrode disposed in saidsecond region and adjacent said passageway, said electrode means havinga charge thereon that creates a field that extends along said passagewayand into said first region for attracting ionized gas in said first'region into said second region.

7. A pump for transferring at least a portion of the gas present in afirst region of high vacuum into a second region of low Vacuum, saidpump comprising the combination of a wall separating said regions fromeach other, said wall having an opening therein that is effective topermit molecules of said gas to travel between saidregions, electronaccelerating means disposed adjacent to said opening for creating afield therein, means operatively interconnected with said electrodemeans for energizing said electrode means to cause free electrons totravel through said openings and between said regions with sufiicientvelocity to ionize at least a portion of the gas molecule in said firstregion to thereby form an electrically non-conductive plasma thatextends through said opening and between said regions, and an ioncollector disposed in the region of low vacuum for collecting theionized gas molecules.

8. A pump for transferring at least a portion of the gas present in afirst region of high vacuum to a second region of low vacuum, said pumpcomprising the combination of a wall disposed between said region forseparating said vacuums from each other, said wall having an openingtherein for interconnecting said regions with each other whereby some ofthe molecules in said vacuums may travel between said regions, magneticmeans disposed adjacent said wall for creating a magnetic fiux fieldwith the -lines of fiux extending through said opening and between saidregions, center electrodes means d isposed adjacent the said wall andsubstantially aligned with said opening, high frequency means forenergizing said electrodes means with an alternating potential forcausing free-electrons to oscillate along said lines of fiux and in saidfirst region with sufiicient velocity to cause ionization of at least aportion of the gas molecules in said first region, an end electrodedisposed in alignment with one end of the center electrode, and meansfor applying a potential to said end electrode for repelling theoscillating electrons so as to define the end of their` oscillations.

9. A pump for transferring at least a portion of the gas present in afirst region of high vacuum into a second region of low vacuum, saidpump comprising the cornbination of a wall disposed between said regionsfor separating said vacuums from each other, said wall having an openingtherein for interconnecting said regions with each other whereby some ofthe molecules in said vacuums may travel between said regions, meansdisposed adjacent said wall for creating a magnetic iiux eld with thelines of iiux extending through said opening and between said regions,electrode means disposed adjacent said Wall and substantially alignedwith said opening, an alternating source operatively inter-connectedwith said electrode means for energizing said electrode means at a highfrequency for causing free electrons to oscillate along said lines of uxthrough said opening and between said regions with suicient velocity tocause ionization of at least a portion of the gas molecules in saidfirst region, and an electrode disposed in said second region adjacentsaid opening and having a polarity for attracting the ionized moleculesin said iirst region.

10. A pump for transferring at least a portion of the gas present in aiirst region of high vacuum to a second region of low vacuum, said pumpcomprising the corn- |bination of a wall disposed between said regionsfor separating said vacuums from each other, said wall having an openingtherein for interconnecting said regions with each other whereby someyof the molecules in said vacuums may travel -between said regions, aiirst electrode disposed on one of said wall in substantial alignmentwith said opening, an additional electrode'disposed adjacent saidopening for causing free electrons to oscillate through said opening andbetween said regions in substantia-l alignment with said electrodes at asuicient velocity to cause ionization of at least a portion of the gasmolecules in said first region, said pair of electrodes having anegative potential for repelling said electrons and limiting theamplitude of their oscillations.

11. A pump for transferring at least a portion of a gas present in afirst region of high vacuum to a second region of low vacuum, said pumpcomprising a wall disposed between said regions for separating saidvacuums from each other, said wall having an opening therein forinterconnecting said regions with each other whereby some of themolecules in said vacuum may travel between said regions, a firstelectrode disposed on one side of said wall in substantial alignmentwith said opening and having a negative potential for repelling saidelectrons, an additional electrode disposed adjacent said opening forcausing a stream of free electrons to oscillate through said opening andinto said first region with sufficient velocity to ionize at least aportion of the gas in said iirst region, and a third electrode disposedin said second region adjacent said opening and having a potential thatwil-1 attract the ions in said first region.

12. A pump for transferring at least a portion of a gas from a iirstregion of high vacuum to a second region of low vacuum, said pumpcomprising a wall disposed between said region for separating saidvacuum from each other, said wall having an opening therein forinterconnecting said regions with each other whereby some of themolecules in said vacuums may travel between said regions, a iirstelectrode disposed on one side of said wall in substantial alignmentwith said opening, magnetic means positioned to create a ux iield withthe ux lines extending through said opening, electron accelerating meansadjacent said opening and aligned with said flux iield for directing astream of free electr-ons through said opening and into said irst regionwith suiiicient velocity to ionize at least a portion of the gas in saidrst region, and a third electrode disposed in said second regionadjacent said opening and having a charge for attracting the ions fromsaid iirst region into said second region.

13. A pump for removing at least a portion of the gas in a containerenclosing a high vacuum, said pump comthrough said first region with asuiiicient velocity to` ionize at least a portion of the gas in said rstregion,' electrodes disposed adjacent the opposite ends of saidi openingand having negative charges for limiting the amount of travel of saidelectrons, and an electrode disposed in said second region adjacent saidopening for attracting ions from said first region.

14. The combination of claim 13, including;

a source of high frequency energy interconnected with4 Said cylinder,said source bein-g effective to excite the cylinder at a high frequencywhereby the free elec:-`

trons will oscillate. 15. A pump for removing at least a portion of thegas in a -container enclosing a high vacuum, said pump comprising thecombination of a housing enclosing a iirst` region of high vacuum andbeing adapted to be interconnected with said container to form acommunication between said vacuums, a second housing enclosing a secondregion of low vacuum, an opening extending between said regions forinterconnecting said regions with eachother whereby some of themolecules in said vacuums may travel i between said regions, magneticmeans positioned to create a magnetic iiux iield -with the lines of uxextending axially of said opening to deiine electron paths, acylindrical elec-` trode disposed relative to said opening for creatinga iield `therein that is eiiective to accelerate free electrons axiallyof said opening and along the paths and parallel to said` lines of flux,said cylindrical electrode being energized to give said electrons asuicient velocity to ionize at leasta portion of the gas in said iirstregion, electrodes positioned adjacent theopposite ends of said openingand in said magnetic tie-ld, said electrodes having a negative potentialto limit the amount of travel of said electrons, and an ad-` ditionalnegatively charged electrode disposed in said second region adjacentsaid -opening and outside of said mag-` netic iield for attracting ionspresent in said first region.` 16. A pump for removing at least aportion of the gas` in a container enclosing a high vacuum, said pump'conv` prising the combination-of a housing enclosing :a first region ofhigh vacuum and being adapted to be interconnected with said containerto form a communication between said vacuums, said housing having a pairof sub,`

stantially parallel arms, a second housing enclosing said arms andforming a second region of low vacuum, at least` one openingin each ofsaid arms, said openings being positioned to register with each otherand to interconriect said regions with each other whereby gas moleculesin said vacuums may travel between said regions, an elec-l trodeaccelerator disposed between said arms arid in sub-` stantial alignmentwith said openings for causing free elec,- trons to oscillate throughsaid openings and between said regions with sufficient velocity toionize at least a portion of the gas in said arms, and an ion collectordisposed in the region of low vacuum for receiving the ions produced bythe accelerated free ions.

17. A pump for removing at least a portion of the gas` in a containerenclosing a high vacuum, said pump comi prising the combination yof ahousing enclosing a first region of high vacuum and being adapted to beintei-,4

connected with said container to form a communication between saidvacuums, said housing having a pair of substantially parallel arms, asecond housing enclosing said arms and forming a second region of lowvacuum, at least one opening in each of said arms, said openings beingpositioned to register with each other and to interconi nect saidregions with each other whereby gas molecules in saidv vacuuml maytravel between said regions, magnetic means disposed on the oppositesides of said Iarms for creating a fiux field that extends through saidopenings and into said first region, electrode means disposed adjacentsaid arms and in substantial alignment with said openings for causingfree electrons to oscillate along said lines of flux through saidopenings and between said regions with sufficient velocity to ionize atleast a portion of the gas in said arms.,

18. A pump for removing at least a portion of the gas in a containerenclosing la high vacuum, said pump-comprising the combination of ahousing enclosing a first region of high vacuum and being adapted to beinterconnected with said container to form a communication between saidvacuums, said housing having a pair of substantially parallel arms, asecond housing enclosing said arms andV a second region of low vacuum,at least one opening in each of said arms, said openings beingpositioned to register with each other and to interconnect said regionswith each other whereby gas molecules in said vacuum may travel betweensaid regions, magnetic means disposed on the opposite sides of said armsfor creating a flux field that extends through said openings and intosaid first region, a cylindrical electrode disposed between said armsand in substantial alignment with said openings, means for energizingsaid cylindrical electrode to cause free electrons to oscillate alongthe lines of flux through said openings and said regions with sufiicientvelocity -to ionize at least a portion of the gas in said arms.

19. A pump for removing at least a portion of the gas in a containerenclosing a high vacuum, said pump cornprising the combination of ahousing enclosing a first region of high vacuumand being adapted to beinterconnected with said container to form a communication between saidvacuums, said housing having a pair of substantially parallel arms, asecond housing enclosing said arms and a second region of low vacuum atleast one opening in each of said arms said openings being positioned toregisterwith each other and to interconnect said regions with each otherwhereby gas molecules in said vacuum may travel between said regions,electrode disposed between said arms and in substantial alignment withsaid openings, means for energizing said cylindrical electrode means tocause free electrons to oscillate along the lines of flux through saidopenings and between said regions with sufficient velocity to ionize atleast a portion of the gas in said arms, and a collector electrodedisposed in said first region for collecting said ions.

20. In a device for transferring a gas from a region of high vacuum to aregion of low vacuum, the combination of:

a passageway extending between said regions,

cold electrode means adjacent said passageway, and

power supply means interconnected with said electrode means, said powersupply means being effective to energize said electrode means with asufficient potential to accelerate the free electrons axially of saidpassageway Iand through said regions with a sufficient velocity toionize gas molecules in the passageway.

21. In a device for transferring a gas from a first region of highvacuum to a second region of low vacuum, the combination of:

a passageway extending between said regions,

first cold electrode means positioned adjacent said passageway,

means for energizing said electrode means with a sufftcient potential tocause the free electrons normally present in at least one of saidregions to oscillate axially of said passageway and through said firstregion with sufficient velocity to ionize at least a portion of the gasin said first region, and

second cold electrode means disposed in said second region adjacent saidpassageway and having a polarity to attract -ions in said first region.

22. Means for transferring at least a portion of the gas present in afirst region of high vacuum into a second region of low vacuum, saidmeans comprising the combination of:

a passageway extending between said regions for interconnecting saidregions with each other,

electron accelerating means positioned adjacent said passageway and-having a potential for accelerating free electrons along a path thatextends through at least said first region with sufficient velocity toionize at least a porti-on of any gas present therein,

magnetic means disposed adjacent the passageway to create magnetic fluxlines that extend axially of the passageway so as to make said pathsextend axially of the passageway, said electron accelerating means beingspaced from the paths of said accelerated electrons so as to preventcollision between the electrons and the accelerating means.

23. Means for transferring at least a portion of the gas present in afirst region of high vacuum into a second region of low vacuum, saidmeans comprising the cornbination of a passageway extending between saidregions for interconnecting said regions with each other,

electron accelerating means positioned adjacent said passageway andhaving a potential to create a field for accelerating free electronsalong a path that extends through at least said first region withsufficient velocity to ionize at least a portion of said gas therein,

magnetic means disposed adjacent the passageway to create magnetic fiuxlines that extend axially of the passageway so .as to make said pathsextend axially of the passageway, and

electrode means disposed in said second region adjacent said passageway,said electrode means -having a potential thereon that creates a field insaid passageway that repels the free electrons accelerated along thepassageway and thereby forms an end to the path at a point that isspaced from the electrode means and attracts the ionized gas.

24. A pump for transferring at least a portion of the gas present in afirst region of high vacuum into a second region of low vacuum, saidpump comprising the combination of:

a wall disposed between said regions for separating said vacuums fromeach other, said wall having an opening therein for interconnecting saidregions with each other whereby some of the molecules in said vacuumsmay travel between said regions,

a vacuum pump interconnected with one of the first of the regions forremoving gas molecules from the region,

means disposed adjacent said Wall for creating a magnetic flux fieldwith the lines of flux extending through said opening and between saidregions to form electron paths,

electron accelerating means disposed adjacent said wall andsubstantially aligned with said opening,

a pair of electrode means disposed on the opposite sides of saidelectron accelerating means and adjacent the ends of said paths, atleast one of the electrode means being disposed in the first region,

a high frequency power supply interconnected with the electronaccelerating means for energizing said accelerating means for causingfree electrons to oscillate along the paths defined by the lines of fluxand through said opening and between said regions with sufficientvelocity to Icause ionization of at least a portion of the gas moleculesin said first region, and

power supply means interconnected with the pair of electrodes formaintaining the electrodes at la potential for repelling the freeelectrons so as to define the ends of the paths, said power supply meansbeing effective to maintain the electron means in said first region at apotential for attracting the ionized gas molecules in said passageway.

References Cited by the Examiner UNITED STATES PATENTS 12 5/1957 Fosteret al. 230-69 i 7/1958 Santeler 230-69 2/ 1962 Ellis 23.0-69

FOREIGN PATENTS 6/ 1958 Germany 4/ 1934 Germany. 10/ 1954 Great Britain.

LAURENCE V. EFNER, Primary Examiner.

1. IN A DEVICE FOR TRANSFERRING A GAS FROM A REGION OF HIGH VACUUM TO AREGION OF LOW VACUUM THE COMBINATION OF A PASSAGEWAY EXTENDING BETWEENSAID REGIONS, ELECTRODE MEANS ADJACENT SAID PASSAGEWAY, AND MEANS FORENERGIZING AT LEAST A PORTION OF SAID ELECTRODE MEANS WITH ANALTERNATING VOLTAGE TO CAUSE FREE ELECTRONS TO OSCILLATE AXIALLY OF SAIDPASSAGEWAY AND THROUGH SAID REGIONS, AND A COLLECTOR DISPOSED IN THEREGION OF LOW VACUUM.